"Hot spots" are areas of the body that are painful to the touch. Hot spots, also called enthesitis, can occur in people with ankylosing spondylitis (AS). Entheses are the locations where tendons and ligaments attach to the bones, and "-itis" means inflammation. Enthesitis causes soreness and swelling.1
Where tendons and ligaments attach to the bones
The progression of AS
AS progresses at different speeds in different individuals, and there is no single pattern that is common to all people with AS. Researchers believe that enthesitis is the first area of inflammation that occurs with AS.2 As these hot spots are subjected to chronic inflammation, the bone begins to wear away. The body then rebuilds the bone tissue, but too much bone can be formed, causing a fusion of the joint or calcification of the spinal ligaments, called syndesmophytes.3
Other causes of enthesitis (body pain)
In addition to AS, enthesitis can be caused by injury or overuse of an area, such as what occurs in sports.1 Enthesitis may also be a symptom of other conditions like psoriatic arthritis, or chronic inflammatory conditions like rheumatoid arthritis.1,2
Common sites of enthesitis in people with AS
Common locations of enthesitis in people with spondyloarthritis like AS include2:
How is enthesitis (body pain) evaluated?
Enthesitis can be evaluated during a physical examination or through the use of imaging technology, such as a magnetic resonance imaging (MRI) scan.4 One evaluation tool that was developed to assess enthesitis in people with AS is called the Maastricht Ankylosing Spondylitis Enthesitis Score (MASES). The MASES tool outlines 13 points on the body that should be evaluated by touch by a healthcare professional. These points are located around the pelvis bones, the spine, and the heels. Other tools that have been developed include the Leeds Entheses Index (LEI), the University of California, San Francisco (UCSF) index, and the Berlin index. Each of these tools uses a different number and pattern of points, and there is no clear recommendation on which is best. These tools may be used during diagnosis and to evaluate how well a particular treatment is working.5
How is enthesitis (body pain) treated?
Enthesitis is treated along with the other symptoms of AS with a combination of medication, exercise, and physical therapy. Medications for AS include6,7:
- Non-steroidal anti-inflammatory drugs (NSAIDs), which can help relieve pain and inflammation
- Biologic medications, which may help slow or stop the progression of the disease by blocking key processes or compounds involved in the inflammatory response
- Corticosteroids, which may be used for short-term relief of inflammation
- Slow-acting anti-rheumatic drugs (SAARDs), which may help relieve pain and inflammation, especially in those who cannot take biologic medications